An exhaust aftertreatment system (ATS) is associated with an engine of a machine. Typically, the exhaust ATS of the engine is coupled to an exhaust gas pipe of the engine at an inlet port defined on a housing of the exhaust ATS. The exhaust ATS treats and reduces oxides of nitrogen (NOx) and unburnt hydrocarbons present in exhaust gas flow, prior to the exhaust gas flow exiting to atmosphere. The exhaust ATS includes an exhaust substrate, such as a Diesel Oxidation Catalyst (DOC), for treating and reducing the unburnt hydrocarbons present in the exhaust gas, and promoting the oxidation of NO to NO2.
Typically, a distance between the inlet port defined in the housing and the exhaust substrate disposed within the housing may be large enough to provide adequate flow uniformity before the exhaust gas impinges upon a face of the exhaust substrate. Design restrictions may result in less available space for the exhaust ATS, and hence the distance between the inlet port and the face of the exhaust substrate may have to be reduced. However, reducing the distance between the inlet port and the face of the exhaust substrate may affect uniformity of the exhaust gas flow and may further degrade performance of the exhaust ATS.
US Patent Publication number US 2012/0151902 discloses a biased reductant mixer for an engine exhaust aftertreatment system. The biased reductant mixer assists in an introduction and conversion of a reductant introduced by an injector. According to the '902 patent publication, a contact area of the biased reductant mixer may be varied so as to provide a greater impingement region for a reductant spray to hit against and cause the reductant spray to break up so as to create more turbulence and further help in conversion of the reductant spray into ammonia.